For a considerable number of years, polymers of various types have been incorporated into a variety of cleaning and personal use cleansing compositions for a variety of purposes. For example, polymers are used in powdered laundry detergents as production assistance, builder assistance, and anti-redeposition agents. In liquid laundry products, they are used as thickeners, and in automatic dishwasher liquids as builders and softeners and as thickeners; in dry dishwasher formulations as builders and softeners.
In the field of personal use skin cleansing compositions, ideally such compositions should be both mild to the skin and give the user's skin a desirable smooth and slippery feel. It is known to incorporate cationic polymers into cleansing bar compositions to effect skin conditioning. In U.S. Pat. No. 5,064,555 and its related U.S. Pat. No. 4,820,447, there is disclosed skin cleansing soap bars comprising soap and a hydrated cationic guar-gum polymer, the addition of which is said to improve the mildness of the soap bar. According to the patents, the soap bars incorporate a hydrated cationic polymer having a molecular weight of from about 1000 to about 3,000,000 with it being preferred that such polymer be a cationic guar-gum polymer having a molecular weight in the range of 2500-350,000. The inventors state it is essential that the cationic polymer be hydrated to achieve uniform distribution of the polymer in the bar. It is further stated that the preferred cationic polymers are of the cationic guar-gum class, examples being JAGUAR C-14-S, C-15 and C-17 previously available from Celanese Corporation and now available from Rhone-Poulenc, inc. It is further disclosed that the polymers require a relatively large amount of water for their hydration. As an example, for JAGUAR C-15 the ratio of polymer to water is about 9 to 1; for JAGUAR C-14S, the ratio is about 19 to 1. From a reading of the patents, it is clear that hydrating the cationic polymer is most important to a successful use of such polymer in a bar soap product. It is also clear that the need to hydrate the polymer is not only an extra step in the soap making process, but requires additional energy to dry the soap to its appropriate moisture level because of the incorporation of the additional water.
It would therefore be a surprising advance in the soap-making art to provide a process for incorporating cationic polymers of the type disclosed in the aforementioned patents and particularly to incorporate cationic guar-gum polymers in soap compositions without the need to hydrate the polymer either prior to or during the soap-making process. It would also be an important advance that the incorporation of such so-called "dry" polymers be accomplished with very little or no gritty feeling to the bar compositions. In short, it would be an important advance to obtain the benefits of the use of cationic guar-gum polymers in bar products as disclosed in the aforementioned patents, without the need to hydrate the polymers.